单项选择题
A.fuel valves；exhaust valve B.exhaust valves；inlet valve C.fuel valves；inlet valve D.exhaust valves；fuel valve
In a two-stroke engine, there are always a series of op...
单项选择题In a two-stroke engine, there are always a series of openings known as （）, and in some circumstances, there are also openings known as （）, in the part of the cylinder liner.
A.scavenging air ports；exhaust ports B.inlet ports；scavenging air ports C.scavenging air ports；inlet ports D.exhaust ports；inlet ports
If the engine is naturally aspirated, or is a small hig...
单项选择题If the engine is naturally aspirated, or is a small high-speed type with a centrifugal turbocharger, the period of valve overlap（）,ie when both valves are（）, will be and the exhaust valve will close some 10°top dead canter（）.
A.open；short；after B.closed；short；after C.open；long；before D.closed；long；before
（）is the main reason that reduces the power advantage o...
单项选择题（）is the main reason that reduces the power advantage of a two-stroke engine over a same size four-stroke one to about（）
A.Inefficient scavenging；twice B.Inefficient scavenging；1~8 times C.Fewer strokes in a circle；twice D.Fewer strokes in a circle；1~8 times
